BAGHDAD — Many were dressed as if for a wedding: men in suits and ties, women in fine veils, even young children in holiday clothes. But the Sunni Arabs were lined up at the polling stations for a battle, their last-ditch attempt to stop a constitution they feel will break up Iraq.

Shiites and Kurds also turned out in strength in crucial parts of the country to support the charter in Saturday's referendum, which will determine the shape of the nation's young democracy after decades of dictatorship.

Reactions and turnouts differed from city to city and region to region throughout Iraq on Saturday.

• BAGHDAD: Balloting began poorly in Azamiyah, the capital's Sunni Arab stronghold, when a rocket exploded near a voting center at 8:30 a.m., slightly wounding one civilian.

As the day progressed, however, droves of people turned up to vote at heavily guarded polling stations in the middle-class quarter of northern Baghdad that hugs the Tigris River.

Sunni-led insurgents had threatened to kill fellow Sunnis in areas such as Azamiyah who ignored the militants' call for a boycott. Still, many in Azamiyah showed up to vote "no" to defeat a constitution they believed favors Kurds and Shiites and could lead to the breakup of Iraq.

Youssef Ibrahim al-Shimiri, a 76-year-old retired nurse, arrived at one polling station with his wife and several of his children. Wearing a traditional white Arab robe and fiddling with his worry beads, he said he had voted "no."

"This is not democracy. There can be no democracy if it arrives on tanks, and children and women are killed every day," he said, referring to the continued presence of U.S. forces who led the invasion of Iraq in 2003.

Another voter, Jilan Shaker, 22, a laborer wearing shorts and plastic sandals, agreed.

"This is all wrong. I said 'no' to a constitution written by the Americans," he said.

• HILLAH: There was a party-like atmosphere in some neighborhoods of this largely Shiite Muslim city, about 60 miles south of Baghdad, where residents turned car and home radios up to blare out songs praising Iraq and Shiite religious leaders.

At Hamurabi elementary school, polling station number 2, voters had to pass through barricades and were searched by police before moving inside to vote. Iraqi soldiers were stationed on the school roof.

Zhayah Ajrish, accompanied by her 5-year-old daughter, Zahraa, said she voted "yes." Her daughter insisted on going along to see the ballots.